Process of making granular nitrate of ammonia.



- grains of any desired size,

' stant the liquor.

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0! me am mans O1 mom Specification of Lettershtent.

I0 Drawing. Application filed Hay I8, 1912, Rn. 688,344. Renewed July 28, 191. Serial 8e.

To all whom it may concern:

Be it known that I, Fnnnnmcx L. Gamer,- of Media, in the countybf Delaware, and-in the State of, Pennsylvania, have invented a certain new and useful Improvement in Processes of Making Granular Nitrate of Ammonia, and do hereby declare that the following is a full, clear, and exact description thereof.

The object of my invention has been to provide a process of producing nitrate of ammonia in granular form, whereby nitrate of ammonia can be produced in grains of any desired size, and particularly globular and to such ends my invention consists in the process of making granular nitrate of ammonia hereinafter specified.

In general, my process may be illustrated by the process described in the patent to Russell S. Penniman, No. 448,361, patented March 17th, 1891, except as hereinafter stated.

I have found that by supplying the ammonium nitrate liquor to the graining pen a a? the Penniman apparatus in condition so that it shall have a. certain temperature of crystallization, I can produce grains of am monium nitrate of a proximately a desired size. If the liquor have a relatively high temperature of'crystallization, the ains of ammonium nitrate will be relative y large. If the ammoniunrnitrate have a tem rature of crystallization which is relatively low, the resulting grains of ammonium nitrate will be relatively small.

In the practice of my process by the Pennimen apparatus, the ammonium nitrate liqnor is concentrate in the pans D and D; that is, the water the liquor is evaporated and the amount of water present in the liquor determines the temperature of crystallination. When any given sample of ammonium nitrate liquor is,allowed to cool, a thermometer immersed in such liquor will show a falling temperature until the crys' tallizing point is reached, at which time the readin on the thermometer becomes conor a short space of time before it again begins to fall with the loss of heat by This point on the thermometer reading, where the temperaturebecomes constunt. represents the crystalhzing temperature. Another indication .of the of ryml1iafi0lt is also minus in am. 65 the nitrate begins to assumea mushy at time the of crystallization is reached. intake practice of my proeem, from time to the concentration progresses in one of the ans D, I take samples of the liquor theren and test for t e temperature of crystallizatiom In this manner I continue the concentration of the liquor in the concentrating an until it has reached a point where it as the desired temperature of crystalhzation, and I then allow it to pass into the granulating pan a, where it is treated as stated in the said fiplatent, and assumes a granular form. I d that the cooling of the concentrated liquor in the graining pen a should not be too rapid as it would interi'ere with the uniformity of the size of grains produced.

As a specific illustration of the manner 30f the ractice of my process, if it is desired to pr uce ammonium nitrate of which not more than will be held on a 40 mesh standard sieve, and at least of which Wlll pass a 100 mesh sieve, but usually from to 90% of which will sieve, the following proce ure may be used: A crystallizing temperature of the evaporated liquor in the high pan should be from 275 to 280F. This crystallizing temperature can be determined b taking a. small dipper or lndleful from t e high an, and stirring it with a s n or spat a, while watchin a standarfiliemical thermometer held in t e ladle during the stirring. As the liquor reaches its crystallizing int it commences to get mushy, at which time the reading on the thermometer becomes constant for a short space of time. The mushy state of the ammonium nitrate occurs at the same.

time and may be used as a check on the thermometer reading. If a crystallizing temperature of from 300 to 305 F. is used, the point and temperature of crystallization is determined as before, and a coarse hard granular product will be obtained and not more than 5% will be held on a 10 mesh standard sieve, and not more than 5% will pass a. mesh standard sieve;

By my process, the grains of ammonium nitrate are substantial y globular and look as the 100 mesh.

something like water-worn gravel. In such form, the ammonium nitrate les easily ab sorbs moisture from the atmosphere, and is therefore more permanent 1nd stable in its character.

I claim:

1. The process of making granular ammonium nitrate, which consists in emulating ammonium nitrate liquor at a de iite degree of concentration according to the size of 2."?110 roses of making granular ammonium nitrate, which consists in crystalhzing and ammonium nitrate liquor a. definite egree of concentration actothesizeofgrainsdosired.

promofmakinggranularunmotrate,wlnchconsistsin nium varying the of concentration of ammonium nitrata liquor according to the size of grains desired, and stirring such liquor while crystallizing it. i

4. The processofmakinggranularammonium nitrate, which consists in concentrating ammonium nitrate. liquor to a recletermined gonfitmtgilon 8mm size of gram car an 000' westn-nng' it.

5. The proces of granular nium nitrate, co in concentrating ammonium nitrate liquor to a predeter-e mined goncentratm according to the; of gram esirecl, an crystalhzmg' su nor by stirring and aeratang, while cooling it.

In testimony that I claim the foregoing I have hereunto set my hand.

(1 Known, CmronnA, Woon DISCLAIMER.

1,l31,36'1.-Fmdcrick Laren Gallup, Media Pa. Pimrnss oF'MAiuNn GRANULAR Nrmxrn or AMMONIA. Patent dated March 9, 1M5. Disclaimer filed March 26, 1925, by the assignec, E. l. du Pont dc [Yemeni-s (f.- flompany.

Hereby enters its disclaimer to such parts of the thing patented as it docs not choose to claim or to hold by virtue of the above-mentioned patent 01' assignments as follows:

To the process specified in claim 1, except as applied to the mnccntration of ammonium nitrate li llOl'S to crystallizing temperatures at which an appreciableamount of water is sti l contained in the liquor when cooling is begun.

To the process specified in claim 2, except when the. step of crystallization is 50 carried out as to Cool the ammonium nitrate liquor relatively slowly and to a degree. of concentration at which an appreciable amount of water is stilleontained in the liquor when cooling is "1"]. 3

To the process specifie in c-laim4, except when the ammonium-nitrate liquor is cooled relatively slowly. 7

[Ofiqial Gazette May 5, 1925.]

DISCLAIMER.

1,131,361.-Frederick Larm flail-up, Media, Pa. PROCESS OF MAKING GRANULAI! Nrriu'n: 01- Ammmm. IatenLdatc-d March 9, 1915. Disclaimer filed October 28, 1925, by the amignee, If. I. (la lo'ut de Nemours and Company.

Hereby enters its disclainwr to such parts of the thing )utented as it does not choose to claim or-to hold by virtue of the above-mutational patient. or assignments as follows:

o the process specified in claims 1 and 3 as applied to the production of small, fine grains of ammonium nitrate.

[Ofli'cial Gazette November 94, 192-5.] 

